The engulfment of precipitate by extension twinning in Mg–Al alloy. (November 2020)

• Record Type: Journal Article
• Authors: Tang, Xiao-Zhi; Guo, Ya-Fang
• Is Part Of: Scripta materialia. Number 188(2020)
• Page Start: 195
• Page End: 199
• Publication Date: 2020-11
• Subjects: Magnesium alloys -- Precipitation -- Twinning -- Molecular dynamics -- Strain rate; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2020.07.020
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: To understand the strengthening mechanism of precipitate against twin-mediated plasticity in magnesium–aluminum alloys, the measurements of the increase in the critical resolved shear stress due to impediment on twin thickening are accomplished based on atomistic simulation, specifically at a significantly low strain rate of 1.7 × 10 6 s −1 . Results show conspicuous coupled effect of temperature and strain-rate on the precipitation strengthening. The strengthening effect vanishes if coherent twin boundary migration is purely stress-driven without thermal activations, due to the back-stress dominating over Orowan stress. At a finite temperature the strengthening effect becomes observable, and is distinctly amplified by high strain rates. Graphical abstract: Image, graphical abstract